Has anyone tried a 12AU7 in V2 of Rocket?

[loctal]

I tried a 12AU7 as the second valve (the CF) in my Rocket. There was no loss in the tone of the amp. The only difference that I could hear was a slight increase in the crunchy sound when cranked. Both the 12AX7 and the 12AU7 sound very good. I would enjoy hearing of your experiments.

[ampdoc1]

I've built 4-5 TW Express-like amps, and I've never used a full compliment of 12AX7s,...just absolutely too much hiss. I generally use an AX7 for the PI, and mix or match AT7s, AY7s, Au7s and 5751s for the first two stages. Lots quieter and still very gainy and responsive.

a'doc1

[keewee]

yea, The CF is a good choice for a 12au7 tube since, 1) there is no voltage gain and is general used as a buffer with good input impedance and output impedance matches and works well to drive the next stage. 2) the cathode to grid breakdown voltages are better for most au7 tubes I have prematurely burnt out 12ax7 tubes as CF because of this. 12ax7 as voltage amps au7 are good current sources. My 2 cents..